EJ38, D'Addario's most popular 12-string set, offers the ideal balance of volume, projection and comfortable playability. Designed for all makes and models of 12-string acoustic guitars. Preferred for its warm, bright, and well balanced acoustic tone. Environmentally friendly, corrosion resistant packaging for strings that are always fresh. Made in the U.S.A. for the highest quality and performance. String Gauges: Plain Steel 0.01/0.1, 0.014/0.014, Phosphor Bronze Wound 0.023/0.008(p), 0.03/0.012(p), 0.039/0.018(p), 0.047/0.027(w).